Taking Wutong Mountain Rhododendron moulmainense ecological landscape forest in Shenzhen City as an example,the value of the forest was assessed by constructing an ecological service value assessment system and accoun...Taking Wutong Mountain Rhododendron moulmainense ecological landscape forest in Shenzhen City as an example,the value of the forest was assessed by constructing an ecological service value assessment system and accounting method.The assessment results showed that the total ecosystem service value of R.moulmainense ecological landscape forest was 13.195 billion yuan,and the top three services included the value of forestry products,the value of biodiversity maintenance and the value of leisure and recreation,indicating that the ecosystem service of Wutong Mountain R.moulmainense ecological landscape forest in Shenzhen has great ecological and economic value,especially in forestry products,biodiversity maintenance,and leisure and recreation.展开更多
In order to actively implement the Convention on Biological Diversity and help Shenzhen build a "park city" and a model of beautiful China, the concepts of landscape ecology, landscape urbanism and bio frien...In order to actively implement the Convention on Biological Diversity and help Shenzhen build a "park city" and a model of beautiful China, the concepts of landscape ecology, landscape urbanism and bio friendly city are introduced to build an evaluation system for biodiversity friendly parks in Longhua District, and explore the relationship between "bio friendly living space" and "city". According to the evaluation system, the Guanlan Printmaking Base scores a total of 273 points, which is rated as a relatively friendly level. In order to coordinate the development between the city and the biosphere and contribute to the goal of building a biodiversity based urban park, the construction of a biodiversity friendly park in Guanlan Printmaking Base is carried out in terms of comprehensive design, plant community construction and biodiversity friendly facilities construction according to the construction principles of biological priority guidance, functional integration and diversification, respect for the park's regionality, and valuing the reachability of natural space.展开更多
In this study, graphene sheets are prepared under a hydrogen atmosphere without a catalyst, and the growth mechanism of graphene by direct current arc discharge is investigated experimentally and numerically. The size...In this study, graphene sheets are prepared under a hydrogen atmosphere without a catalyst, and the growth mechanism of graphene by direct current arc discharge is investigated experimentally and numerically. The size and layer numbers of graphene sheets increase with the arc current.Distributions of temperature, velocity, and mass fraction of carbon are obtained through numerical simulations. A high current corresponds to a high saturation temperature, evaporation rate, and mass density of carbon clusters. When the carbon vapor is saturated, the saturation temperatures are 3274.9, 3313.9, and 3363.6 K, and the mass densities are 6.4×1022,8.42×1022, and 1.23×1023 m-3 under currents of 150, 200, and 250 A, respectively. A hydrogen-induced marginal growth model is used to explain the growth mechanism. Under a high current, the condensation coefficient and van der Waals force increase owing to the higher saturation temperature and mass density of carbon clusters, which is consistent with experimental results.展开更多
[Objectives] This study was conducted to understand the species diversity of plant communities in the Xiaolingjiao area of Anhui Province,and to analyze the current status of the plant resources of Symptocos.[Methods]...[Objectives] This study was conducted to understand the species diversity of plant communities in the Xiaolingjiao area of Anhui Province,and to analyze the current status of the plant resources of Symptocos.[Methods]Quadrats with a total area of 3 600 m^2 were set up in typical evergreen broad-leaved forests in the Xiaolingjiao area of Huangshan Mountain.[Results] There were 79 species of woody plants in the quadrats,belonging to 53 genera of 29 families.As seen from the age class structure,evergreen trees such as Castanopsis eyrei and Eurya nitida were growing populations,and Cyclobalanopsis glauca,Cunninghamia lanceolata,Pinus massoniana and Loropetalum chinense were declining populations.The age class structure of each species in Symplocos was of the growing type,and the various populations had not reached a stable state and would grow continuously.The communities had a tendency to develop to evergreen broad-leaved forests.[Conclusions]This study provides a scientific basis for the protection,development and utilization of Symplocos plants.展开更多
Based on modern observations,historical proxy data,and climate model simulations,this paper provides a comprehensive overview of the past,present and future evolution characteristics of the Atlantic Meridional Overtur...Based on modern observations,historical proxy data,and climate model simulations,this paper provides a comprehensive overview of the past,present and future evolution characteristics of the Atlantic Meridional Overturning Circulation(AMOC),as well as its impact on the surface air temperature(SAT)at regional and hemispherical scales.The reconstruction results based on the proxy data indicate that the AMOC has weakened since the late 19th century and experienced overall weakening throughout the 20th century with low confidence.Direct observations show that the AMOC weakened during 2004–2016,but it is not possible to distinguish between its decadal variability and long-term trend.Climate models predict that if greenhouse gas emissions continue to increase,AMOC will weaken in the future,but there will not be a sudden collapse before 2100.For the thermodynamic effects of AMOC,the increased surface heat flux release and meridional heat transport(MHT)over the North Atlantic associated with the strong AMOC cause an increase in the hemispherical SAT.At the millennial scale,climate cooling(warming)periods correspond to a weakened(strengthened)AMOC.The enhanced MHT of a strong AMOC can affect Arctic warming and thus influence regional SAT anomalies and SAT extremes through mutual feedback between Arctic sea ice and AMOC.In terms of dynamic effects,a strong AMOC modulates the Rossby wave trains originating from the North Atlantic and spreading across mid-to-high latitudes in the Northern Hemisphere and causes an increase in the variabilities in the circulation anomalies over the Ural and Siberian regions.Ultimately,a strong AMOC significantly affects the frequencies of extreme cold and warm events in the mid-to-high latitude regions over Eurasia.In addition,AMOC can also influence regional and global SAT anomalies through its dynamic adjustment of planetary-scale circulation.Decadal variation in AMOC is closely related to the Atlantic Multidecadal Oscillation(AMO).During positive phases of AMO and AMOC,enhanced surface heat fluxes over the North Atlantic lead to abnormal warming in the Northern Hemisphere,while during negative phases,the reverse case occurs.Under high emission scenarios in the future,the possibility of AMOC collapse increases due to freshwater forcing.However,most advanced climate models underestimate the strength of the AMOC and its impact on the AMO and relevant climate change,which presents a major challenge for future understanding and prediction of the AMOC and its climate effects.展开更多
The recruitment of key cells to regeneration sites is a promising strategy to promote functional wound healing.Dermal fibroblasts exhibit a heterogeneous population of cells during homeostasis and in response to injur...The recruitment of key cells to regeneration sites is a promising strategy to promote functional wound healing.Dermal fibroblasts exhibit a heterogeneous population of cells during homeostasis and in response to injury.Papillary fibroblasts play central regulatory roles in the regeneration of skin appendages during wound healing.Inspired by the phenomenon where bait for grass carp can attract grouped grass carps to a fishing spot soon,“Grass Carp Fishing”multifunctional hydrogels,that is,codelivery of an antibody of leucine-rich repeats and immunoglobulin-like domains 1(Lrig1)on the surface of papillary fibroblasts and insulinlike growth factor 1(IGF1)with recruitment function,can recruit papillary fibroblasts.In the experiments,carboxymethyl chitosan showed positive effects in promoting cell proliferation and neovascularization,while dopamine-grafted gelatin was effective in stabilizing the structure and prolonging the degradation time.The sustained release of Lrig1 antibodies and IGF1 from injectable self-healing multifunctional hydrogels persistently accelerated the migration and proliferation of Lrig1+fibroblasts.The in vivo results from a full-thickness cutaneous wound model showed that injectable self-healing multifunctional hydrogel accelerated wound healing and skin regeneration through the recruitment of Lrig1+papillary fibroblasts in wound tissue.Our findings reveal an injectable self-healing multifunctional hydrogel for regeneration,a promising approach to promoting skin wound healing.展开更多
Porous structure in orthopedic prosthesis may reduce micromotion and increase the service life of implants.The purposes of this study were to compare the influence of the tibial stems with solid and porous structures ...Porous structure in orthopedic prosthesis may reduce micromotion and increase the service life of implants.The purposes of this study were to compare the influence of the tibial stems with solid and porous structures in Total Knee Arthroplasty(TKA)on knee joint and prostheses,and to improve the mechanical stability of the host bone by seeking favorable structure for the tibial stem.The Finite Element(FE)models of TKA knee with four different structures in the middle segment of the tibial stem(i.e.,solid,cubic,truncated cubic,and octahedral structures)were constructed.The distributions of von Mises stress in the knee joint,tibial prosthesis and proximal tibia,and the compressive stresses of the tibial prosthesis and ultra-high-molecular-weight polyethylene for the four FE models were analyzed.The results showed that the tibial stem filled with the octahedral structure has the best mechanical performance among the above four types of tibial stems.It could effectively reduce the stress concentration and stress shielding effects,and provide an improved mechanical environment for knee joint after TKA.This study would shed some lights on the design and fabrication of porous implants targeted to biomedical applications.展开更多
The mechanical properties of tissues are pivotal for morphogenesis and disease progression.Recent approaches have enabled measurements of the spatial distributions of viscoelastic properties among embryonic and pathol...The mechanical properties of tissues are pivotal for morphogenesis and disease progression.Recent approaches have enabled measurements of the spatial distributions of viscoelastic properties among embryonic and pathological model systems and facilitated the generation of important hypotheses such as durotaxis and tissue-scale phase transition.There likely are many unexpected aspects of embryo biomechanics we have yet to discover which will change our views of mechanisms that govern development and disease.One area in the blind spot of even the most recent approaches to measuring tissue stiffness is the potentially anisotropic nature of that parameter.Here,we report a magnetic micromanipulation device that generates a uniform magnetic field gradient within a large workspace and permits measurement of the variation of tissue stiffness along three orthogonal axes.By applying the device to the organ-stage mouse embryo,we identify spatially heterogenous and directionally anisotropic stiffness within the mandibular arch.Those properties correspond to the domain of expression and the angular distribution of fibronectin and have potential implications for mechanisms that orient collective cell movements and shape tissues during development.Assessment of anisotropic properties extends the repertoire of current methods and will enable the generation and testing of hypotheses.展开更多
文摘Taking Wutong Mountain Rhododendron moulmainense ecological landscape forest in Shenzhen City as an example,the value of the forest was assessed by constructing an ecological service value assessment system and accounting method.The assessment results showed that the total ecosystem service value of R.moulmainense ecological landscape forest was 13.195 billion yuan,and the top three services included the value of forestry products,the value of biodiversity maintenance and the value of leisure and recreation,indicating that the ecosystem service of Wutong Mountain R.moulmainense ecological landscape forest in Shenzhen has great ecological and economic value,especially in forestry products,biodiversity maintenance,and leisure and recreation.
文摘In order to actively implement the Convention on Biological Diversity and help Shenzhen build a "park city" and a model of beautiful China, the concepts of landscape ecology, landscape urbanism and bio friendly city are introduced to build an evaluation system for biodiversity friendly parks in Longhua District, and explore the relationship between "bio friendly living space" and "city". According to the evaluation system, the Guanlan Printmaking Base scores a total of 273 points, which is rated as a relatively friendly level. In order to coordinate the development between the city and the biosphere and contribute to the goal of building a biodiversity based urban park, the construction of a biodiversity friendly park in Guanlan Printmaking Base is carried out in terms of comprehensive design, plant community construction and biodiversity friendly facilities construction according to the construction principles of biological priority guidance, functional integration and diversification, respect for the park's regionality, and valuing the reachability of natural space.
基金supported by National Natural Science Foundation of China (No. 11765010)the National Key Research and Development Program of China (No. 2019YFC1907900)+2 种基金the Applied Basic Research Programs of Yunnan Provincial Science and Technology Department (No. 202001AW070004)the Freely Exploring Fund for Academicians in Yunnan Province (No. 2018HA006)the Key Laboratory of Resource Chemistry, Ministry of Education (No. KLRCME2001)
文摘In this study, graphene sheets are prepared under a hydrogen atmosphere without a catalyst, and the growth mechanism of graphene by direct current arc discharge is investigated experimentally and numerically. The size and layer numbers of graphene sheets increase with the arc current.Distributions of temperature, velocity, and mass fraction of carbon are obtained through numerical simulations. A high current corresponds to a high saturation temperature, evaporation rate, and mass density of carbon clusters. When the carbon vapor is saturated, the saturation temperatures are 3274.9, 3313.9, and 3363.6 K, and the mass densities are 6.4×1022,8.42×1022, and 1.23×1023 m-3 under currents of 150, 200, and 250 A, respectively. A hydrogen-induced marginal growth model is used to explain the growth mechanism. Under a high current, the condensation coefficient and van der Waals force increase owing to the higher saturation temperature and mass density of carbon clusters, which is consistent with experimental results.
基金Supported by Shenzhen Land Ecological Survey and Evaluation(SZCG2018161498)。
文摘[Objectives] This study was conducted to understand the species diversity of plant communities in the Xiaolingjiao area of Anhui Province,and to analyze the current status of the plant resources of Symptocos.[Methods]Quadrats with a total area of 3 600 m^2 were set up in typical evergreen broad-leaved forests in the Xiaolingjiao area of Huangshan Mountain.[Results] There were 79 species of woody plants in the quadrats,belonging to 53 genera of 29 families.As seen from the age class structure,evergreen trees such as Castanopsis eyrei and Eurya nitida were growing populations,and Cyclobalanopsis glauca,Cunninghamia lanceolata,Pinus massoniana and Loropetalum chinense were declining populations.The age class structure of each species in Symplocos was of the growing type,and the various populations had not reached a stable state and would grow continuously.The communities had a tendency to develop to evergreen broad-leaved forests.[Conclusions]This study provides a scientific basis for the protection,development and utilization of Symplocos plants.
基金supported by the National Natural Science Foundation of China(Grant Nos.41822503 and 42175053)the National Key Research and Development Program(Grant No.2016YFA0601502).
文摘Based on modern observations,historical proxy data,and climate model simulations,this paper provides a comprehensive overview of the past,present and future evolution characteristics of the Atlantic Meridional Overturning Circulation(AMOC),as well as its impact on the surface air temperature(SAT)at regional and hemispherical scales.The reconstruction results based on the proxy data indicate that the AMOC has weakened since the late 19th century and experienced overall weakening throughout the 20th century with low confidence.Direct observations show that the AMOC weakened during 2004–2016,but it is not possible to distinguish between its decadal variability and long-term trend.Climate models predict that if greenhouse gas emissions continue to increase,AMOC will weaken in the future,but there will not be a sudden collapse before 2100.For the thermodynamic effects of AMOC,the increased surface heat flux release and meridional heat transport(MHT)over the North Atlantic associated with the strong AMOC cause an increase in the hemispherical SAT.At the millennial scale,climate cooling(warming)periods correspond to a weakened(strengthened)AMOC.The enhanced MHT of a strong AMOC can affect Arctic warming and thus influence regional SAT anomalies and SAT extremes through mutual feedback between Arctic sea ice and AMOC.In terms of dynamic effects,a strong AMOC modulates the Rossby wave trains originating from the North Atlantic and spreading across mid-to-high latitudes in the Northern Hemisphere and causes an increase in the variabilities in the circulation anomalies over the Ural and Siberian regions.Ultimately,a strong AMOC significantly affects the frequencies of extreme cold and warm events in the mid-to-high latitude regions over Eurasia.In addition,AMOC can also influence regional and global SAT anomalies through its dynamic adjustment of planetary-scale circulation.Decadal variation in AMOC is closely related to the Atlantic Multidecadal Oscillation(AMO).During positive phases of AMO and AMOC,enhanced surface heat fluxes over the North Atlantic lead to abnormal warming in the Northern Hemisphere,while during negative phases,the reverse case occurs.Under high emission scenarios in the future,the possibility of AMOC collapse increases due to freshwater forcing.However,most advanced climate models underestimate the strength of the AMOC and its impact on the AMO and relevant climate change,which presents a major challenge for future understanding and prediction of the AMOC and its climate effects.
基金Funding for this study was provided by the Natural Science Foundation of Jiangsu Province(No.BK20191141)Top Talent Support Program for Young and Middle-aged People of Wuxi Health Committee(Nos.BJ2020044,BJ2020057,and HB2020043)+2 种基金Fundamental Research Funds of Health and Family Planning Commission of Wuxi(No.M202024)the Special Program for Translational Medicine Research of Wuxi Translational Medicine Center(Nos.2020DHYB07 and 2020DHYB03)Key Special Project of Precision Medicine of Wuxi Health Commission(No.J202101).
文摘The recruitment of key cells to regeneration sites is a promising strategy to promote functional wound healing.Dermal fibroblasts exhibit a heterogeneous population of cells during homeostasis and in response to injury.Papillary fibroblasts play central regulatory roles in the regeneration of skin appendages during wound healing.Inspired by the phenomenon where bait for grass carp can attract grouped grass carps to a fishing spot soon,“Grass Carp Fishing”multifunctional hydrogels,that is,codelivery of an antibody of leucine-rich repeats and immunoglobulin-like domains 1(Lrig1)on the surface of papillary fibroblasts and insulinlike growth factor 1(IGF1)with recruitment function,can recruit papillary fibroblasts.In the experiments,carboxymethyl chitosan showed positive effects in promoting cell proliferation and neovascularization,while dopamine-grafted gelatin was effective in stabilizing the structure and prolonging the degradation time.The sustained release of Lrig1 antibodies and IGF1 from injectable self-healing multifunctional hydrogels persistently accelerated the migration and proliferation of Lrig1+fibroblasts.The in vivo results from a full-thickness cutaneous wound model showed that injectable self-healing multifunctional hydrogel accelerated wound healing and skin regeneration through the recruitment of Lrig1+papillary fibroblasts in wound tissue.Our findings reveal an injectable self-healing multifunctional hydrogel for regeneration,a promising approach to promoting skin wound healing.
基金the National Natural Science Foundation of China(Nos.11872095,11702110)the Natural Science Foundation of Jilin Province(No.20200201260JC)the Graduate Innovation Fund of Jilin University(No.101832018C194)for financial support.
文摘Porous structure in orthopedic prosthesis may reduce micromotion and increase the service life of implants.The purposes of this study were to compare the influence of the tibial stems with solid and porous structures in Total Knee Arthroplasty(TKA)on knee joint and prostheses,and to improve the mechanical stability of the host bone by seeking favorable structure for the tibial stem.The Finite Element(FE)models of TKA knee with four different structures in the middle segment of the tibial stem(i.e.,solid,cubic,truncated cubic,and octahedral structures)were constructed.The distributions of von Mises stress in the knee joint,tibial prosthesis and proximal tibia,and the compressive stresses of the tibial prosthesis and ultra-high-molecular-weight polyethylene for the four FE models were analyzed.The results showed that the tibial stem filled with the octahedral structure has the best mechanical performance among the above four types of tibial stems.It could effectively reduce the stress concentration and stress shielding effects,and provide an improved mechanical environment for knee joint after TKA.This study would shed some lights on the design and fabrication of porous implants targeted to biomedical applications.
基金This work was funded by the Canadian Institutes of Health Research(CIHR)Natural Sciences and Engineering Research Council of Canada(NSERC),Ontario Research Funds,and Medicine by Design–New Ideas Program.
文摘The mechanical properties of tissues are pivotal for morphogenesis and disease progression.Recent approaches have enabled measurements of the spatial distributions of viscoelastic properties among embryonic and pathological model systems and facilitated the generation of important hypotheses such as durotaxis and tissue-scale phase transition.There likely are many unexpected aspects of embryo biomechanics we have yet to discover which will change our views of mechanisms that govern development and disease.One area in the blind spot of even the most recent approaches to measuring tissue stiffness is the potentially anisotropic nature of that parameter.Here,we report a magnetic micromanipulation device that generates a uniform magnetic field gradient within a large workspace and permits measurement of the variation of tissue stiffness along three orthogonal axes.By applying the device to the organ-stage mouse embryo,we identify spatially heterogenous and directionally anisotropic stiffness within the mandibular arch.Those properties correspond to the domain of expression and the angular distribution of fibronectin and have potential implications for mechanisms that orient collective cell movements and shape tissues during development.Assessment of anisotropic properties extends the repertoire of current methods and will enable the generation and testing of hypotheses.
